1. Field of the Invention
The present invention relates to an apparatus and method for improving Video Telephony (VT) quality. More particularly, the present invention relates to an apparatus and method for improving Video Telephony (VT) quality by using meta-data determined by processing received radio signal strength which is network status information during VT of a portable terminal that uses a 3G-324M protocol for the VT in a mobile communication network.
2. Description of the Related Art
In a 3rd Generation (3G) network, which is a mobile communication network, Video Telephony (VT) is conducted using a 3G-324M protocol which is an international standard. Maximum capacity of video, audio, and data recommended by the standard varies depending on capacity of a data transmission device, but is typically 64 kbps. Herein, the maximum capacity is 48 to 50 kbps for video, 4 to 12 kbps for audio, and 2 kbps for data.
A VT service based on the 3G-324M protocol requires mutual compatibility between mobile communication service providers, and is defined in the international standard in order to provide simple and accurate services between users.
As a VT protocol, the 3G-324M is a telephony method in which protocol exchange is performed between terminals in an end-to-end manner. To establish a connection, information is exchanged by initially performing several processes for protocol signaling.
Such a process is greatly affected by the radio signal strength of the 3G network. A data transmission/reception rate varies depending on the radio signal strength of the 3G network, which has a great effect on a connection success rate and call quality.
However, since the protocol is a data transfer protocol between terminals, maximum transmission/reception capacity is limited, and also a 3G network operation of a mobile communication service provider is limited. Due to such a disadvantage, a final VT user inevitably receives poor quality video/audio services.
In particular, a fixed bandwidth of 48 kbps allocated for video transmission of VT is insufficient to provide high quality video. Since a status and property of a network through which data is transmitted in practice are not considered, VT quality is frequently degraded.
The radio signal strength is not considered in the 3G network in the VT of the related art, and thus the following problems are present.
First, since a network status of a peer terminal is not considered in a signaling process in which protocol data is exchanged, it is difficult to improve a connection success rate and quality.
Second, since audio/video codecs used in a call connection are determined always according to priority, a codec with better quality cannot be selectively used according to the network status.
Third, when data allocated to each channel is not completely filled due to the use of the fixed bandwidth, the remaining capacity is filled with stuffing data, and thus it is difficult to improve audio/video quality because of ineffective use of the bandwidth.
Fourth, since a protocol operates irrespective of the network status, VT quality deteriorates in comparison with terminal performance.
Therefore, a need exists for an apparatus and method for improving VT quality using meta data based on a radio signal.